Field of the Invention
The present invention relates to a teleconference terminal apparatus, teleconference system, and teleconference method for carrying out a teleconference using a communications line.
Description of the Prior Art
Conventionally, as a teleconference system for carrying out a teleconference among a plurality of points, there has been proposed a configuration comprising a plurality of mobile units capable of transmitting voice signals and image signals, a parent station connected to these mobile units via a communications network, an image transmission device provided in the parent station and capable of identifying a voice signal and switching between motion and still images, and a plurality of monitors connected to the image transmission device and capable of displaying images of all the mobile units.
In the above configuration, still images of conditions of all of the mobile units are displayed on the monitors. Then, image signals obtained by each mobile unit recording a motion image are transmitted along with voice signals to the image transmission device of the parent station, and a mobile unit in-use is identified by the image transmission device on the basis of the voice signals from each mobile unit, whereby only an image projected on the monitor corresponding to the mobile unit in-use is switched from a still to a motion image. Accordingly, still images of the conditions of all of the mobile units can be monitored and a motion image of the mobile unit in-use can be displayed on the monitor without selecting operation particularly on the parent station side (Japanese Unexamined Patent Publication No. H5-153585).
However, in the teleconference system described in the above publication document, since all of the mobile units transmit image signals of motion images to the parent station regardless of whether the mobile units are in use, the traffic of the communications network between the mobile units and the parent station easily expands excessively, thus the problem is that the amount of data of the image signals should be reduced although the quality of the motion images deteriorates.